The outcomes of total knee arthroplasty in morbidly obese patients: a systematic review of the literature

Intermittent tourniquet compared to throughout tourniquet use during Total Knee Arthroplasty in patients with Body Mass Index of 30 or more: A retrospective cohort study

Background

Tourniquet use during total knee arthroplasty (TKA) reduces bleeding which optimises bone-cement interface for prosthesis stability and improves surgical field visualisation. However, prolonged usage can lead to complications and poorer outcomes. Some surgeons advocate for intermittent tourniquet application. Limited literature exists for patients with high body mass index (BMI). This study aims to compare the outcomes of intermittent tourniquet (IT) to throughout tourniquet (TT) use among obese patients undergoing primary TKA for knee osteoarthritis.

Methods

This was a retrospective cohort study. In the TT group, tourniquet was inflated from the beginning and released once the bone cement has hardened. In the IT group, tourniquet was inflated at the beginning, released after initial incision and haemostasis, then inflated again during cementation. Tourniquet was released once the bone cement had set. Categorical outcome measures were analysed using Chi-squared or Fisher's exact test. T-test or Kruskal-Wallis test were used for continuous data.

Results

When comparing IT to TT among patients with BMI≥30 (IT n = 48, TT n = 47), the mean duration of surgery was shorter in the TT group (p < 0.05). The difference in haemoglobin drop between the two groups was not statistically significant from post-operative day three onwards. There was no difference in transfusion rate (p > 0.05). ROM was greater in the IT group up to three weeks post-operatively (p < 0.05). When comparing patients with BMI <30 (n = 71) and BMI≥30 (n = 48) with IT use, there was no statistically significant difference in ROM and LOS.

Conclusion

Patients with BMI≥30 in the IT group had greater ROM in the initial post-operative period. Although operative time and blood loss were greater among the IT group, there was no difference in transfusion rate. Outcomes of TKA performed with IT were similar for patients with BMI≥30 and BMI <30. The authors recommend intermittent tourniquet use during TKA for patients with BMI≥30.

Level of evidence

3.

Preoperative and Postoperative Weight Change has Minimal Influence on Health Care Utilization and Patient-Reported Outcomes Following Total Knee Arthroplasty

As obesity becomes more prevalent, more patients are at risk of lower extremity osteoarthritis and subsequent total knee arthroplasty (TKA). This study aimed to test (1) the association of preoperative weight change with health care utilization and (2) the association of pre- and postoperative weight changes with failure to achieve satisfaction and minimal clinically important difference (MCID) in Knee injury and Osteoarthritis Outcome Score for pain (KOOS-Pain) and function (KOOS-PS) 1 year after TKA. Prospectively collected monocentric data on patients who underwent primary TKA were retrospectively reviewed. Multivariable logistic regression assessed the influence of BMI and weight change on outcomes while controlling for confounding variables. Outcomes included prolonged length of stay (LOS >3 days), nonhome discharge, 90-day readmission rate, satisfaction, and achievement of MCID for KOOS-Pain and KOOS-PS. Preoperative weight change had no impact on prolonged LOS (gain, p = 0.173; loss, p = 0.599). Preoperative weight loss was associated with increased risk of nonhome discharge (odds ratio [OR]: 1.47, p = 0.003). There was also increased risk of 90-day readmission with preoperative weight gain (OR: 1.27, p = 0.047) and decreased risk with weight loss (OR: 0.73, p = 0.033). There was increased risk of nonhome discharge with obesity class II (OR: 1.6, p = 0.016) and III (OR: 2.21, p < 0.001). Weight change was not associated with failure to achieve satisfaction, MCID in KOOS-Pain, or MCID in KOOS-PS. Obesity class III patients had decreased risk of failure to reach MCID in KOOS-Pain (OR: 0.43, p = 0.005) and KOOS-PS (OR: 0.7, p = 0.007). Overall, pre- and postoperative weight change has little impact on the achievement of satisfaction and clinically relevant differences in pain and function at 1 year. However, preoperative weight gain was associated with a higher risk of 90-day readmissions after TKA. Furthermore, patients categorized in Class III obesity were at increased risk of nonhome discharge but experienced a greater likelihood of achieving MCID in KOOS-Pain and KOOS-PS. Our results raise awareness of the dangers of using weight changes and BMI alone as a measure of TKA eligibility.

Evidence-based and Patient-centered Indication for Knee Arthroplasty - Update of the Guideline

Knee arthroplasty is one of the most frequently performed operations in Germany, with approximately 170000 procedures per year. It is therefore essential that physicians should adhere to an appropriate, and patient-centered indication process. The updated guideline indication criteria for knee arthroplasty (EKIT-Knee) contain recommendations, which are based on current evidence and agreed upon by a broad consensus panel. For practical use, the checklist has also been updated.For this guideline update, a systematic literature research was conducted in order to analyse (inter-)national guidelines and systematic reviews focusing on osteoarthritis of the knee and knee arthroplasty, to answer clinically relevant questions on diagnostic, predictors of outcome, risk factors and contraindications.Knee arthroplasty should solely be performed in patients with radiologically proven moderate or severe osteoarthritis of the knee (Kellgren-Lawrence grade 3 or 4), after previous non-surgical treatment for at least three months, in patients with high subjective burden with regard to knee-related complaints and after exclusion of possible contraindications (infection, comorbidities, BMI ≥ 40 kg/m2). Modifiable risk factors (such as smoking, diabetes mellitus, anaemia) should be addressed and optimised in advance. After meeting current guideline indications, a shared decision-making process between patients and surgeons is recommended, in order to maintain high quality surgical management of patients with osteoarthritis of the knee.The update of the S2k-guideline was expanded to include unicondylar knee arthroplasty, the preoperative optimisation of modifiable risk factors was added and the main indication criteria were specified.

Comparison of Outcomes in Obese Patients after Total Knee Arthroplasty with Neutral or Mild Varus: A Retrospective Study with 8-Year Follow-Up

OBJECTIVES

Residual varus after total knee arthroplasty (TKA) can affect functional outcomes, which may worsen in the presence of obesity. However, no studies were found to compare the outcomes of obese patients involving postoperative residual mild varus or neutral. The aim of this study was to compare postoperative complications and prosthesis survival, and functional outcomes for knees of obese patients with neutral or mild varus after TKA.

METHODS

We retrospectively reviewed 188 consecutive obese patients (body mass index ≥30 kg/m2) at our hospital who underwent TKA due to varus knee osteoarthritis from January 2010 to December 2015. The mechanical hip-knee-ankle axis angle was measured in all patients at admission and discharge. Knee functions were retrospectively assessed based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society Knee Score (KS-KS), Knee Society Function Score (KS-FS), Forgotten Joint Score (FJS), and range of motion (ROM). Continuous data were compared between knees with neutral or mild varus alignment using analysis of Student's t test or variance or the Kruskal-Wallis test as appropriate. For multiple comparisons of outcomes, we used Bonferroni-Dunn method to adjust p-values. Categorical data were compared using the chi-squared test.

RESULTS

Of the 156 knees in 137 obese patients who completed follow-up for a mean of 8.32 ± 1.47 years, 97 knees were corrected from varus to neutral and 54 knees were kept in mild residual varus. Patients with mild varus knees had significantly WOMAC (8.25 ± 8.637 vs. 14.97 ± 14.193, p = 0.009) and better FJS (86.03 ± 15.607 vs. 70.22 ± 30.031, p = 0.002). The two types of knees did not differ significantly in KS-KS, KS-FS, or ROM. Although one patient with a neutral knee had to undergo revision surgery, there was no significant difference between two groups.

CONCLUSIONS

For obese patients with osteoarthritis, preservation of residual varus alignment after TKA can improve functional outcomes without compromising prosthesis survival.

Prevalence of anemia and association with outcome in joint arthroplasty - is there a difference between primary and revision cases?

PURPOSE

Anemia has been shown to be a modifiable pre-operative, patient factor associated with outcome following arthroplasty. The aims of this retrospective study were to (1) ascertain the prevalence of preoperative anemia in patients undergoing primary and revision hip and knee arthroplasty at a tertiary referral center and (2) to test the association with outcome and whether it differs between primary and revision cases.

METHODS

All hip and knee primary and revision arthroplasties performed at a Canadian academic, tertiary-care, arthroplasty center between 2012 and 2017 were included in this study. The study group consisted of 5944 patients, of which 5251 were primary Total Hip and Knee Arthroplasties or Hip Resurfacings and 693 were revision arthroplasties (65% hip revisions/35% knee revisions). Anemia was classified as per WHO definition (hemoglobin < 130 g/L for men and < 120 g/L for women). All anemic patients were grouped into mild, moderate or severe anemia. Length-of-stay, perioperative transfusion-rate, 90-day readmission, overall complication rate and reoperation rates were recorded. The effect of preoperative anemia and the effect of severity of the anemia was evaluated through multivariable regression analysis controlling for relevant covariates.

RESULTS

Preoperatively, 15% (786/5251) of the primary patients and 47% (322/693) of the revision arthroplasty patients were anemic preoperatively. Anemic revision patients were 3.1 times more likely (95% CI: 1.47-6.33) to obtain blood transfusions during the hospital stay, compared to a 4.9 times higher risk in primary patients. The odds ratio to sustain any postoperative complication if anemic was 1.5 times higher (95% CI: 0.73-3.16) in revision patients and 1.7 in primary cases. In addition, the 90-day readmission rate among both groups was 1.6 times higher in anemic patients. Furthermore, anemic revision patients had a 5.3 days longer length of stay (95% CI: 2.63-7.91), compared to only 1 additional day in anemic primary patients (95% CI: 0.69-1.34).

CONCLUSION

In this study cohort, the prevalence of anemia in patients awaiting revision arthroplasty was 3 times higher (46.6%) than in primary arthroplasty patients (18.7%). Preoperative anemia was associated with similarly, inferior outcomes in both groups. To reduce postoperative complications and the "burden" associated with anemia, these findings strongly recommend optimizing the preoperative hemoglobin in all arthroplasty patients. However, revision patients are affected more frequently, and particular attention must therefore be taken to this growing group in the future.

LEVEL OF EVIDENCE

Level III.

Substantial Weight Loss May Not Improve Early Outcomes of Total Knee Arthroplasty in the Morbidly Obese

BACKGROUND

Body mass index (BMI) cutoffs for morbidly obese patients otherwise indicated for total knee arthroplasty (TKA) have been widely proposed and implemented, though they remain controversial. Previous studies suggested that a 5% reduction in BMI may be associated with fewer postoperative complications. Thus, the purpose of this study was to determine whether a substantial reduction in preoperative BMI in morbidly obese patients improved 90-day outcomes after TKA.

METHODS

There were 1,270 patients who underwent primary TKA at a single institution and had a BMI > 40 recorded during the year prior to surgery. Patients were stratified into three cohorts based on whether their BMI within 3 months to 1 year preoperatively had decreased by ≥ 5% (228 patients [18%]); increased by ≥ 5% (310 [24%]); or remained unchanged (within 5%) (732 [58%]) on the day of surgery. There were several baseline differences between the cohorts with respect to medical comorbidities. The rate of 90-day complications and six-week patient-reported outcome measures were compared via univariate and multivariable analyses.

RESULTS

On univariate analysis, individual and total complication rates were similar between the cohorts (P > .05). On multivariable logistic regression, the risk of complications was similar in patients who had decreased versus unchanged BMI (OR [odds ratio] 1.0; P = .898). However, there was a higher risk of complications in the increased BMI cohort compared to those patients who had an unchanged BMI (OR 1.5; P = .039). The six-week patient-reported outcome measures were similar between the cohorts.

CONCLUSIONS

Patients who have a BMI > 40 who achieved a meaningful reduction in BMI prior to TKA did not have a lower rate of 90-day complications than those whose BMI remained unchanged. Furthermore, considering that nearly one in four patients experienced a significant increase in BMI while awaiting surgery, postponing TKA may actually be detrimental.

Role of bariatric surgery in reducing periprosthetic joint infections in total knee arthroplasty. A systematic review and meta-analysis

BACKGROUND

Obesity represents an epidemic of rising numbers worldwide year after year. In the Orthopedic field, obesity is one of the major causes leading to osteoarthritis needing Total Joint Arthroplasty (TJA). Still, contextually, it represents one of the most significant risk factors for joint replacement complications and failures. So, bariatric Surgery (BS) is becoming a valuable option for weight control and mitigating obesity-related risk factors. This review of the literature and meta-analysis aims to evaluate periprosthetic joint infections (PJI) and surgical site infections (SSI) rates in patients who underwent TKA after BS compared to obese patients without BS.

METHODS

Systematic review was performed according to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines up to October 2023. We included longitudinal studies comparing obese patients who underwent total knee arthroplasty after bariatric surgery (study group) and obese patients who underwent TKA (control group). The surgical site infection and Periprosthetic joint infection rate were compared among groups using a meta-analytical approach.

RESULTS

The online database and references investigation identified one hundred and twenty-five studies. PJI rate differed significantly among groups, (z = -21.8928, p < 0.0001), with a lower risk in the BS group (z = -10.3114, p < 0.0001), for SSI, instead, not statistically significance were recorded (z = -0.6784, p = 0.4975).

CONCLUSIONS

The current Literature suggests that Bariatric Surgery can reduce infectious complications in TKA, leading to better outcomes and less related costs treating of knee osteoarthritis in obese patients.

Robotic-Assisted Total Knee Arthroplasty in Obese Patients

Background

Robotic-assisted systems have gained popularity in total knee arthroplasty (TKA). The purpose of this study was to evaluate operative characteristics and radiographic outcomes of obese patients undergoing robotic-assisted TKA.

Methods

A retrospective review of consecutive cases performed by a single surgeon was performed from January 1, 2016, to January 31, 2022. Adult patients with body mass index ≥35 kg/m2 who underwent primary TKA using a computed tomography-assisted robotic system were compared to patients who underwent primary TKA using conventional instrumentation. Demographics, preoperative and postoperative radiographic measurements, and intraoperative outcomes were compared between cohorts. In total, 119 patients were identified, 60 in the robotic-assisted cohort and 59 in the conventional instrumentation cohort.

Results

Age, body mass index, and estimated blood loss were not significantly different between the cohorts. The robotic-assisted cohort experienced longer tourniquet times (93.3 vs 75.5 minutes, P < .001). Preoperative hip-knee-ankle angle (HKA) was similar between the robotic-assisted and conventional cohorts (8.4° ± 4.9° vs 9.3° ± 5.3°, P = .335). Postoperative HKA was 2.0° ± 1.4° in the robotic-assisted group and 3.1° ± 3.23° in the conventional group (P = .040). The proportion of patients with postoperative HKA > 3° of varus or valgus was 9 of 60 (15.0%) in the robotic-assisted cohort compared to 18 of 59 (30.5%) using conventional instrumentation (P = .043).

Conclusions

Obese patients treated with robotic-assisted TKA had postoperative alignment closer to neutral and fewer postoperative radiographic outliers than patients treated with conventional instrumentation. The results of this study support use of robotic-assisted technologies in TKA, particularly in obese patients.

Lever sign test shows high diagnostic accuracy for anterior cruciate ligament injuries: A systematic review and meta-analysis of 3299 observations

PURPOSE

Injuries of the anterior cruciate ligament (ACL) are common knee injuries among active and younger patients. The Lever Sign Test (LST) is a relatively newer test, of which the accuracy is disputed in the existing literature. The aim of this study was to assess the accuracy with and without anesthesia of the Lever Sign test in the literature.

METHODS

PRISMA guidelines were followed, studies were identified using PubMed, EMBASE and Google Scholar. All studies that reported accuracy of LST performed by a clinical professional were included. Integrity of ACL was confirmed using magnetic resonance imaging or arthroscopy. Sensitivity and specificity were calculated using uni- and bivariate methods.

RESULTS

After inclusion, 3299 observations in 2516 patients were included from 23 studies. Mean age was 31.8 years and 64.2% were male. Without anesthesia, sensitivity was 79.2% (95% CI 68.7-86.9) and specificity was 92.0% (95% CI 82.2-96.6). An area under the curve (AUC) of 86.1% was found. With anesthesia, sensitivity was 86.6% (95% CI 68.0-95.2), specificity was 93.4% (95% CI 84.5-97.3) and the AUC was 91.6%.

CONCLUSION

The Lever Sign test shows very good to excellent accuracy for ACL injury, and is a useful tool for clinical practice.

Influence of body mass index on severity of rotator cuff tears

BACKGROUND

Research on the relationship between obesity and rotator cuff tears (RCTs) has been limited to the impact of obesity on the results of arthroscopic repair of RCTs; thus, a need for rigorous research controlling for other factors affecting RCTs is warranted, especially to better understand the impact of body mass index (BMI) on RCT severity.

METHODS

A retrospective study of admission records contained in electronic medical records pertaining to patients who were admitted for RCT repair on 1 shoulder between January 2018 and July 2022 was conducted. In total, 386 patients were included. In accordance with guidance regarding obesity from Taiwan's Ministry of Health and Welfare, patients were divided into three groups: underweight or normal weight (BMI <24.0 kg/m2), overweight (BMI 24.0-26.9 kg/m2), or obese (BMI ≥27.0 kg/m2). Magnetic resonance imaging was used to assess RCT severity in terms of four parameters: Patte stage (PS), fatty infiltration (FI), anteroposterior tear size (AP), and retraction size. Multinomial logistic regression analysis was performed on PS and FI grade data, and multiple linear regression analysis was performed on AP tear size and retraction size in order to analyze impact.

RESULTS

Our results revealed that the average age of the 386 patients was 63.41 years (SD = 9.29) and the mean BMI was 25.88 (SD = 3.72) kg/m2. We found significant differences in PS (P = .003), FI (P < .001), retraction size (P = .001), and AP tear size (P = .001) among patients who were underweight or normal weight, overweight, and obese. After controlling for other risk factors, including age, gender, RCT-prone occupation, duration of shoulder pain prior to surgery, history of shoulder injury, and tobacco use, we found that obese patients had higher severity levels in PS (B = 1.21, OR = 3.36, P = .029), FI (B = 1.38, OR = 3.96, P < .001), retraction size (β = 0.18, P = .001), and AP tear size (β = 0.18, P = .001) compared to underweight or normal weight patients.

CONCLUSIONS

Our study demonstrates that a correlation exists between BMI-measured obesity and RCT severity. We therefore suggest that adults control their weight given that maintaining a healthy weight is highly associated with better shoulder health.

The Association Between Mental Health, Substance Use Disorder, and Outcomes After Total Joint Arthroplasty

BACKGROUND

Prior studies suggest that distressed patients or those who have poor mental health have inferior postoperative outcomes when compared to nondistressed patients. However, these studies typically do not account for substance use or other comorbidities often found in this population, which can independently contribute to postoperative complications. This study sought to control for these factors and assess if a diagnosis of a mental health condition is directly associated with worse outcomes after total joint arthroplasty.

METHODS

A retrospective chart review was performed for 3,182 patients who underwent a total hip arthroplasty and 4,430 patients who underwent a total knee arthroplasty. Diagnosis of the mental health disorders included depression, anxiety disorder, adjustment disorder, bipolar disorder, trauma, stressor-related disorder, and schizophrenia or schizoaffective disorder. Multivariable analyses were performed to control for alcohol use, drug use, tobacco use, body mass index, and a comorbidity index.

RESULTS

When controlling for body mass index and Charlson comorbidity index, no statistically significant associations were found between a diagnosis of any mental health condition or a specific diagnosis of depression or anxiety, and 90-day readmission, reoperation, or 1 year mortality for patients undergoing total knee arthroplasty or total hip arthroplasty.

CONCLUSIONS

When accounting for confounding factors, there does not appear to be a direct association between diagnosis of any of the psychiatric conditions we studied and outcomes after primary total joint arthroplasty. While prior studies suggest addressing the mental health condition may improve outcomes, this study suggests that preoperative medical optimization and potentially addressing substance use may be more effective strategies.

Association between Obesity and Short-Term Patient-Reported Outcomes following Total Knee Arthroplasty: A Retrospective Cohort Study in Japan

Background: This study investigated the association between obesity and short-term patient-reported outcomes after total knee arthroplasty (TKA). Methods: The primary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index's (WOMAC) pain and function scores. Data were collected preoperatively and 2 and 4 weeks after surgery. Patients were stratified into three groups based on body mass index (BMI): normal weight (BMI < 24.99 kg/m2), overweight (25 ≤ BMI < 29.99 kg/m2), and obese (BMI ≥ 30 kg/m2). The associations between BMI and the WOMAC pain and function scores were assessed using generalized linear mixed models. Results: Among the 102 patients (median age: 75.0, women [85.3%]), 29.4%, 48.0%, and 22.5% were normal weight, overweight, and obese, respectively. The mean pain and function scores at baseline were similar across the BMI-stratified groups (p = 0.727 and 0.277, respectively). The pain score significantly improved 2 weeks post-surgery (p = 0.001). The function score improved significantly 4 weeks post-surgery (p < 0.001). The group and group-by-time interaction effects lacked statistical significance. Conclusions: All patients statistically and clinically showed relevant pain reduction and functional improvement shortly after TKA, irrespective of their obesity status. These data may help healthcare professionals discuss the expectations of pain amelioration and functional improvement with TKA candidates.

Risk Factors Associated With Quadriceps Tendon Extensor Mechanism Disruption Following Total Knee Arthroplasty

BACKGROUND

Quadriceps tendon extensor mechanism disruption is an infrequent but devastating complication after total knee arthroplasty (TKA). Our knowledge of specific risk factors for this complication is limited by the current literature. Thus, this study aimed to identify potential risk factors for quadriceps tendon extensor mechanism disruption following TKA.

METHODS

A retrospective cohort analysis was performed using the PearlDiver Administrative Claims Database. Patients undergoing TKA without a prior history of quadriceps tendon extensor mechanism disruption were identified. Quadriceps tendon extensor mechanism disruption included rupture of the quadriceps tendon, patellar tendon, or fracture of the patella. Patients who had a minimum of 5 years of follow-up after TKA were included. A total of 126,819 patients were included. Among them, 517 cases of quadriceps tendon extensor mechanism disruption occurred (incidence 0.41%). Hypothesized risk factors were compared between those who had postoperative quadriceps tendon extensor mechanism disruption and those who did not.

RESULTS

On multivariate analysis, increased Charlson Comorbidity Index (odds ratio (OR): 1.10, 95% confidence interval (CI) [1.07 to 1.13]; P < .001), obesity (OR: 1.49, 95% CI [1.24 to 1.79]; P < .001), and fluoroquinolone use any time after TKA (OR: 1.24, 95% CI [1.01 to 1.52]; P = .036) were significantly associated with quadriceps tendon extensor mechanism disruption.

CONCLUSIONS

Our study identified the incidence of quadriceps tendon extensor mechanism disruption following TKA as 0.41%. Identified risk factors for quadriceps tendon extensor mechanism disruption after TKA include an increased Charlson Comorbidity Index, obesity, and use of fluoroquinolones postoperatively.

Despite Greater Improvement in Pain and Function Among Obese Patients Shortly After Total Knee Arthroplasty, There is No Difference in Patient-Reported Outcomes and Satisfaction Between Body Mass Index Classes at 1 Year Postoperatively

BACKGROUND

Although obesity may be associated with an increased risk of perioperative and postoperative complications after total knee arthroplasty (TKA), body mass index (BMI) cutoffs for TKA patient selection remain a controversial topic. This study aimed to investigate patient-reported outcomes, satisfaction, and pain among BMI classes at 3 months and 1 year following TKA.

METHODS

A total of 2,365 patients were categorized into Centers for Disease Control BMI classes according to preoperative values. The BMI distribution over the cohort demonstrated 7 underweight, 340 healthy weight, 731 overweight, 666 Class I, 391 Class II, and 230 Class III obesity. Preoperative and postoperative Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), satisfaction, and pain scores were compared by BMI class by Analysis of Variance with pairwise comparisons.

RESULTS

Preoperative KOOS JR scores and satisfaction scores were both significantly greater for healthy weight patients compared to Class III patients (P < .0001). However, KOOS JR, satisfaction, and pain did not vary by BMI class postoperatively. Changes in scores from baseline suggest larger improvements with increasing BMI class, where Class III patients reported the greatest improvements in KOOS JR (23.24 ± 15.67, P < .0001) and pain scores (-3.56 ± 2.65, P < .0001) at 90 days. Significantly greater improvement with increasing BMI was also present at 1-year postoperatively for KOOS JR scores. A total of 85.8% of Class III patients reached the Minimal Clinically Important Difference for KOOS JR at 90 days compared to 76.8% of the healthy weight group (P = .03). Differences between BMI groups in the proportion reaching Minimal Clinically Important Difference at 1 year were not significant.

CONCLUSIONS

Patients of higher BMI reported greater and earlier improvements in satisfaction, knee function, and pain following TKA. Shared decision-making remains paramount to preoperative surgical evaluation. However, rationing of this surgical intervention based on BMI alone may not be warranted.

Socioeconomic inequalities in patient-reported outcome measures of Dutch primary hip and knee arthroplasty patients for osteoarthritis

OBJECTIVE

To study socio-economic inequalities in patient-reported outcomes in primary hip and knee arthroplasty (THA/TKA) patients for osteoarthritis, using two analytical techniques.

METHODS

We obtained data from 44,732 THA and 30,756 TKA patients with preoperative and 12-month follow-up PROMs between 2014 and 2020 from the Dutch Arthroplasty Registry. A deprivation indicator based on neighborhood income, unemployment rate, and education level was linked and categorized into quintiles. The primary outcome measures were the EQ-5D-3L index and Oxford Hip/Knee Score (OHS/OKS) preoperative, at 12-month follow-up, and the calculated change score between these measurements. We contrasted the most and least deprived quintiles using multivariable linear regression, adjusting for patient characteristics. Concurrently, we calculated concentration indices as a non-arbitrary tool to quantify inequalities.

RESULTS

Compared to the least deprived, the most deprived THA patients had poorer preoperative (EQ-5D -0.03 (95%CI -0.02, -0.04), OHS -1.26 (-0.99, -1.52)) and 12-month follow-up health (EQ-5D -0.02 (-0.01, -0.02), OHS -0.42 (-0.19, -0.65)), yet higher mean change (EQ-5D 0.02 (0.01, 0.03), OHS 0.84 (0.52, 1.16)). The most deprived TKA patients had similar results. The higher mean change among the deprived resulted from lower preoperative health in this group (confounding). After accounting for this, the most deprived patients had a lower mean change. The concentration indices showed similar inequality effects and provided information on the magnitude of inequalities over the entire socio-economic range.

CONCLUSION

The most deprived THA and TKA patients have worse preoperative health, which persisted after surgery. The concentration indices allow comparison of inequalities across different outcomes (e.g., revision risk).

Does experience with total knee arthroplasty in morbidly obese patients effect surgical outcomes

INTRODUCTION

Literature examining the risks, benefits, and potential complications of TKA in morbidly obese patients is conflicting. Surgeons with more experience performing TKA on morbidly obese patients may generate superior outcomes. This study sought to assess whether complication rates and implant survivorship in morbidly obese TKA patients varies between high (HV) and low (LV) volume surgeons.

METHODS

A retrospective review was performed to include all morbidly obese (BMI ≥ 40) patients that underwent primary TKA between January 2016 and July 2021 at our high-volume center. Demographics and clinical outcomes were collected and compared between surgeons with a higher morbidly obese TKA volume (> 10 annual cases) and surgeons with a lower morbidly obese TKA volume.

RESULTS

A total of 964 patients (HV 91 [9.4%], LV 873 [90.6%]) were identified. The HV surgeon and LV surgeons had an average annual volume of 15.3 and 5.2 cases, respectively. The average BMI for the HV and LV cohorts were 44.5 ± 3.7 and 44.0 ± 3.6, respectively (p = 0.160). The HV surgeon had significantly lower operative times (105.7 ± 17.4 vs. 110.7 ± 29.6 min, p = 0.018), and a lower 90-day minor complication rate (0.0% vs. 4.7%, p = 0.035). For patients with at least 2-year follow-up, all-cause revision (3.4% vs. 12.5%, p = 0.149) and revision due to PJI (0.0% vs. 5.8%, 0.193) rates were numerically lower in the HV cohort. Improvements in KOOS, JR and VR-12 scores were similar at 3-month and 1-year follow-up. Freedom from all-cause revision (HV: 96.6% vs. LV: 80.4%, p = 0.175) and revision due to PJI (HV: 100.0% vs. LV: 93.6%, p = 0.190, p = 0.190) at latest follow-up did not statistically differ between groups.

CONCLUSION

The HV surgeon had significantly lower operative time and 90-day minor complication rates and numerically lower all-cause revision and revision due to PJI rates when performing TKA in morbidly obese patients. Surgeon's experience may affect surgical outcomes after TKA in morbidly obese patients.

LEVEL OF EVIDENCE

III.

Effects of a Hybrid Teaching Program on Lower Limb Muscle Strength, Knee Function, and Depression in Older Adults After Total Knee Replacement: A Randomized Controlled Trial

The aim of the current study was to evaluate the effects of a nurse-led hybrid teaching program on lower limb strength, knee function, and depression in older adults after total knee replacement (TKR). This was a single-blind, randomized controlled trial. Fifty-two patients who underwent TKR were randomly assigned to either the experimental group (EG; n = 26), which received routine care plus 16 weeks of home rehabilitation through a hybrid teaching program, or the control group (CG; n = 26), which received routine care only. The intervention included pre-discharge face-to-face education, video instructions to follow at home after discharge, and four monthly telephone-based follow ups during the 16 weeks post-surgery. After the 16-week intervention, participants in the EG exhibited improved quadriceps strength, hamstring strength, and Knee Injury and Osteoarthritis Outcome Score (KOOS) compared to those in the CG. Generalized estimating equation analyses revealed a significant group-by-time interaction effect on quadriceps strength, overall KOOS score, and Geriatric Depression Scale-Short Form score. Findings suggest that a nurse-led hybrid teaching program enhances physical and psychological function after TKR when compared to routine care. This hybrid teaching program, involving exercise and postoperative education, proves to be a feasible and cost-effective intervention for improving outcomes in older adults following TKR. Health care teams should consider it as a viable home rehabilitation option for older adults who undergo TKR. [Research in Gerontological Nursing, 17(1), 31-40.].

Severe obesity in total knee arthroplasty occurs in younger patients with a greater healthcare burden and complication rate

BACKGROUND

Knee osteoarthritis in the presence of severe obesity (BMI ≥ 40) is becoming an increasing presentation to healthcare services. When progressing to arthroplasty, this group is known to have higher complication rates.

METHOD

A retrospective cohort study at a tertiary referral centre (UK) with all sequential patients undergoing TKA between 2019 and 2020 included following identification from the UK National Joint Registry. Patients were divided by BMI < 40 and BMI ≥ 40 (86, 16.3%). Analysis of BMI with pre-operative parameters including age, ASA, and blood parameters was performed. Primary outcome was re-operation rate. Secondary outcomes included length of stay, complications, and re-admission.

RESULTS

Five hundred and twenty-eight sequential TKA patients were included. The BMI < 40 group (442 patients, 83.7%) were mean 5.4 years younger (p < 0.001), had a higher ASA grade (p < 0.001) lower albumin (p < 0.001) and higher HbA1c (p < 0.001) than the BMI ≥ 40 group (86 patients, 16.3%). The BMI ≥ 40 group had a higher rate of re-operation (8% vs 2%, p = 0.012), and longer length of stay (mean 1.2 days longer p < 0.001), most commonly due to wound discharge, which alongside dehiscence was significantly higher (11.6% vs 4.3% p = 0.02). Overall, re-admission rates were also higher (18.6% vs 6.1% p = 0.06) with wound dehiscence, superficial infection, and deep infection the most common causes.

CONCLUSIONS

Those patients undergoing TKA with a BMI ≥ 40 are younger and have higher reoperation rates, greater length of stay, higher re-admission rates and more postoperative complications, providing a target for the development of pre-operative optimisation programmes.

Evolution of body mass index and complications rate in severely or morbidly obese patients undergoing total knee arthroplasty

INTRODUCTION

Associations between obesity and knee osteoarthritis or complications after total knee arthroplasty (TKA) are well established. The procedure can significantly improve knee function, favoring weight loss, despite the risk of surgical complications. The main objective of the present study was to assess change in body mass index (BMI) after TKA in patients with severe or morbid obesity (BMI≥35kg/m2). The secondary endpoint was the rate of surgical revision. The hypotheses were that there is no significant change in BMI after TKA and that there is a significant rate of revision.

METHODS

This retrospective descriptive study was conducted for the period June 2009 to December 2019. Thirty-three patients (48 knees) were included: 27 women, 6 men; mean age, 66.5 years (range, 55-80). Preoperatively, 11 patients had BMI 35-39.9kg/m2 and 22 BMI≥40 (including 11 with BMI≥45kg/m2). The preoperative axis was in varus for 35 patients (73%, including 54%≥10°) and in valgus for 13 (27% including 33%≥10°). Radiological and clinical evaluation was carried out at 3 months and 1 year postoperatively. At≥2 years, change in BMI and EQ5D functional score were established by telephone survey; >5% change in BMI was considered significant.

RESULTS

Mean follow-up was 6.9±2.3 years (range, 2.9-10.5). Twenty-five patients (38 knees) were included for analysis. Mean postoperative BMI was 41±5kg/m2, with a mean decrease of 1.2±3.6kg/m2. At the last follow-up, BMI had increased in 8 patients (32%), including 3 by >5% (12%), and decreased in 16 (64%), including 7 by >5% (28%). The higher the baseline BMI, the greater the decrease: for BMI [35-39.9], -0.81 (range, -6.8; +4.3); for BMI [40-44.5],-1 (range, -9; +5.22); and for BMI>45, -1.54 (range, -3.97; +1.3). EQ5D averaged 0.75 at last follow-up. The higher the preoperative BMI, the more satisfactory the postoperative EQ5D: EQ5D for BMI [35-39.9]=0.71 (range, 0.36; 1); for BMI [40-44.5]=0.75 (range, 0.45; 1); and for BMI>45=0.80 (range, 0.48; 1). Four early surgical site infections (10.5%) and 2 isolated changes of the tibial component for early loosening (5.2%) required surgical revision.

CONCLUSION

Patients with severe or morbid obesity had a low tendency to lose weight after TKA, but this does not appear to us to be clinically relevant: the functional results were good. Nevertheless, this series showed a significant rate of revision (15%). TKA was feasible in patients with BMI≥35kg/m2, but requires appropriate patient information.

LEVEL OF EVIDENCE

IV.

Does Obesity Impact Outcomes of Total Knee Arthroplasty When Treated by High-Volume Surgeons? A Propensity-Matched Analysis From a High-Volume Urban Center

BACKGROUND

The impact of morbid obesity (MO) on outcomes following total knee arthroplasty (TKA) when performed by high-volume (HV) surgeons has not been investigated. This study aimed to assess complication rates and implant survivorship in MO patients operated on by HV surgeons.

METHODS

Patients undergoing primary, elective TKA between June 2011 and May 2022 with a HV surgeon (top 25% surgeons by the number of primary TKAs per year) were retrospectively reviewed. Patients were stratified by body mass index (BMI) into 3 groups: BMI ≥40 (MO), 30≤ BMI <40 (non-morbidly obese), and BMI <30 (nonobese) and 1:1:1 propensity matched based on baseline characteristics. Of the 12,132 patients evaluated, 1,158 were included in final matched analyses (386 per group). The HV surgeons performed a median of 104 TKAs annually (range, 90-173).

RESULTS

The MO patients had significantly longer surgery duration (P = .006) and hospital lengths of stay (P < .001). The 90-day postoperative complications (P = .38) and readmission rates (P = .39) were comparable between groups. Rates of all-cause, septic and aseptic revision were similar between groups at two-year (P = .30, P = .15, and P = .26, respectively) and the latest follow-up (P = .36, P = .52, and P = .38, respectively). Improvement in Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) scores at 6 months (P = .049) and one year (P = .015) was significantly higher in MO patients.

CONCLUSION

Clinical outcomes and complication rates following TKA by HV surgeons are comparable regardless of obesity status. The MO patients may benefit from referral to experienced surgeons to minimize procedural risks and improve outcomes.

LEVEL OF EVIDENCE

III.

Is there an indication for simultaneous bilateral knee arthroplasty in morbidly obese patients? Should the patients' request for simultaneous operation be considered?

PURPOSE

This study aimed to analyse the safety of simultaneous bilateral total knee arthroplasty (SBTKA) surgery by comparing morbidly obese (MO) patients with obese patients.

METHODS

SBTKA was performed to 494 patients by a single surgeon in a single center between 2014-2020. The patients followed for a mean of 26 months. They were divided into two groups according to body mass index (BMI) as MO (BMI> 40 kg/m2, n = 65) and obese(O) (BMI = 30-39.9 kg/m2, n = 429 patients). The groups were compared in terms of wound healing problems (WHP), mobilization time (MT), operation time (OT), prosthesis infection, aseptic loosening (AL), early complications, revision, and length of hospitalization using univariate and multivariate logistic regression analyses.

RESULTS

Logistic regression analysis revealed significant differences in the clinical outcomes and complications between MO and O patients. Parameters such as length of stay, OT, MT, WHP, debridement, medial retinaculum detachment (MRD) and AL, and short-term complications such as acute kidney injury (AKI), and pulmonary embolism (PE) incidence were significantly higher in the MO group. Among the MO patients, the clinical outcomes were worse than those among the O patients, and the complication incidence was higher.

CONCLUSION

We do not find SBTKA surgery feasible in morbidly obese patients due to the high complication rate and unsatisfactory clinical outcomes. We suggest that the patient's request to undergo SBTKA should not be taken into account, and that staged surgery be preferred.

Stemmed Versus Nonstemmed Tibia in Primary Total Knee Arthroplasty: A Similar Pattern of Aseptic Tibial Loosening in Obese Patients with Moderate Varus. 5-Year Outcomes of a Randomized Controlled Trial

Obesity is linked to early tibial tray failure after primary total knee arthroplasty (TKA) for osteoarthritis (OA), especially in patients with preoperative varus. This study compared standard and stemmed tibiae TKAs in patients with class I and II obesity with varus deformity. Between April 2013 and June 2020, a prospective study was conducted including patients with end-stage OA, body mass index between 30 and 40 kg/m2, and varus <15 degrees. Patients were randomly assigned to TKAs with either standard or long-stemmed tibiae and evaluated 5 years after surgery using the Knee Society Scoring (KSS). The knee society and modified radiographic evaluation systems were used for radiological evaluation. In total, 264 TKAs were performed in 264 patients (134 in the standard group and 130 in the stemmed group). The mean preoperative hip-knee-ankle angles for the standard and stemmed groups were 8.2 ± 3.2 degrees/varus and 9 ± 2.9 degrees/varus, respectively (p = 0.2), which improved to 5.1 ± 3 degrees/valgus and 5 ± 3.5 degrees/valgus after surgery (p = 0.52). There was no statistically significant difference between the objective KSS (92 vs. 92.9; p = 0.84) and the functioning KSS (73.4 vs. 74.8; p = 0.28). There were no aseptic loosening cases or radiographic differences. In-group analysis revealed significant outcomes differences in both groups if preoperative varus was >10 degrees irrespective of the stem design (p < 0.0001). Complications occurred in two patients; one with a late infection and one had a stem-related tibial fracture. Standard tibia TKAs yielded comparable results in obese patients to long-stemmed tibias. No aseptic tibial loosening was observed regardless of stem type, and worse clinical outcomes were associated with greater varus. CLINICAL TRIAL REGISTRY::  registered at http://www.researchregistry.com (researchregistry5717).LEVEL OF EVIDENCE: II; a prospective randomized trial.

Outcomes in revision knee arthroplasty: Preventing reoperation for infection Keynote lecture - BASK annual congress 2023

Revision total knee arthroplasty (TKA) patients have a lower survival rate and lower post-surgical outcomes compared to primary TKA patients. Infection and aseptic loosening are the most common reasons for revision and re-revision TKAs, with infection accounting for nearly half of re-revision cases. To prevent infection, patient optimization addressing obesity, diabetes, malnutrition, and smoking cessation is crucial. Advancements in irrigation solutions, antibiotic-impregnated bone fillers, bacteriophage therapy, and electrochemical therapy hold promise for preventing infection. Technical strategies such as obtaining sufficient component fixation, joint line restoration, and using robot assistance may improve revision TKA outcomes. As the burden of revision TKA continues to rise, substantial efforts remain for mitigating future revision TKAs and their associated complications.

Body Mass Index (BMI) Cutoffs and Racial, Ethnic, Sex, or Age Disparities in Patients Treated With Total Ankle Arthroplasty

Background

The rising prevalence of obesity among American adults has disproportionately affected Black adults and women. Furthermore, body mass index (BMI) has historically been used as a relative contraindication to many total joint arthroplasty (TJA) procedures, including total ankle arthroplasty. The purpose of this study was to investigate potential disparities in patient eligibility for total ankle arthroplasty based on race, ethnicity, sex, and age by applying commonly used BMI cutoffs to the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

Methods

Patients in the ACS-NSQIP database who underwent TAA from 2011 to 2020 were retrospectively reviewed in a cross-sectional analysis. BMI cutoffs of <50, <45, <40, and <35 were then applied. The eligibility rate for TAA was examined for each BMI cutoff, and findings were stratified by race, ethnicity, sex, and age. Independent t tests, chi-squared tests, and Fisher exact tests were performed to compare differences at an α = 0.05.

Results

A total of 1215 of 1865 TAA patients (65.1%) were included after applying the exclusion criteria. Black patients had disproportionately lower rates of eligibility at the most stringent BMI cutoff of <35 (P = .004). Hispanic patients had generally lower rates of eligibility across all BMI cutoffs. In contrast, Asian American and Pacific Islander patients had higher rates of eligibility at the BMI cutoffs of <35 (P = .033) and <40 (P = .039), and White non-Hispanic patients had higher rates of eligibility across all BMI cutoffs. Females had lower eligibility rates across all BMI cutoffs. Ineligible patients were also younger compared to eligible patients across all BMI cutoffs.

Conclusion

Stringent BMI cutoffs may disproportionately disqualify Black, female, and younger patients from receiving total ankle arthroplasty.

Level of Evidence

Level III, retrospective cross-sectional study.

Total Ankle Arthroplasty: Does Obesity Matter?

BACKGROUND

There is limited data evaluating the effect of obesity on outcomes following total ankle arthroplasty (TAA), especially in adequate sample sizes to detect impacts on patient-reported outcomes (PROs). The purpose of this study was to assess the effect of obesity on complication rates and PROs.

METHODS

This was a single-institution, retrospective study of 1093 primary TAA performed between 2001 and 2020. Minimum follow-up was 2 years. Patients were stratified by body mass index (BMI) into control (BMI = 18.5-29.9; n = 615), obesity class I (BMI = 30.0-34.9; n = 285), and obesity class II (BMI > 35.0; n = 193) groups. Patient information, intraoperative variables, postoperative complications, and PRO measures were compared between groups using univariable statistics. Multivariable Cox regression was performed to assess risk for implant failure. Mean follow-up was 5.6 years (SD: 3.1).

RESULTS

Compared to control and class I, class II patients had the lowest mean age (P = .001), highest mean ASA score (P < .001), and greatest proportion of female sex (P < .001) and Black/African American race (P = .005). There were no statistically significant differences in postoperative complications (infection, implant failure, or impingement) across the BMI classes (P > .05).Preoperatively, class II had lower (worse) mean scores for Foot and Ankle Outcome Score pain and ADL subscales than controls (post hoc pairwise P < .001 for both). At final follow-up, both class II and class I had lower (worse) mean Short Musculoskeletal Function Assessment (post hoc pairwise P < .001 and P = .030, respectively) and 36-Item Short Form Health Survey scores (post hoc pairwise P < .001 and P = .005, respectively) than controls.

CONCLUSION

At midterm follow-up, obesity was not associated with increased rates of complications after TAA. Patients with obesity reported worse musculoskeletal function and overall quality of life after TAA but there was no differential improvement in PROs across BMI classes. To our knowledge, this is the largest single-institution study to date examining the effect of obesity on outcomes after primary TAA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Total knee arthroplasty and bariatric surgery: change in BMI and risk of revision depending on sequence of surgery

BACKGROUND

Patients with obesity have a higher risk of complications after total knee arthroplasty (TKA). We investigated the change in weight 1 and 2 years post-Bariatric Surgery (BS) in patients that had undergone both TKA and BS as well as the risk of revision after TKA based on if BS was performed before or after the TKA.

METHODS

Patients who had undergone BS within 2 years before or after TKA were identified from the Scandinavian Obesity Surgery Register (SOReg) and the Swedish Knee Arthroplasty Register (SKAR) between 2007 and 2019 and 2009 and 2020, respectively. The cohort was divided into two groups; patients who underwent TKA before BS (TKA-BS) and patients who underwent BS before TKA (BS-TKA). Multilinear regression analysis and a Cox proportional hazards model were used to analyze weight change after BS and the risk of revision after TKA.

RESULTS

Of the 584 patients included in the study, 119 patients underwent TKA before BS and 465 underwent BS before TKA. No association was detected between the sequence of surgery and total weight loss 1 and 2 years post-BS, - 0.1 (95% confidence interval (CI), - 1.7 to 1.5) and - 1.2 (95% CI, - 5.2 to 2.9), or the risk of revision after TKA [hazard ratio 1.54 (95% CI 0.5-4.5)].

CONCLUSION

The sequence of surgery in patients undergoing both BS and TKA does not appear to be associated with weight loss after BS or the risk of revision after TKA.

Influence of body mass index on early post-operative functional outcomes after total knee arthroplasty: A prospective, clinical and observational study

Background/Purpose: The evidence on the influence of body mass index (BMI) on functional outcomes following total knee arthroplasty (TKA) is conflicting. This study assessed and compared the effect of BMI on early mobility and function after TKA. Methods: Adult patients with osteoarthritis (OA) or rheumatoid arthritis (RA) who received unilateral TKA were recruited and then divided into normal, overweight and obese groups. The pain and functional outcomes of pre/post-TKA were examined using visual analogue scale (VAS) and Lysholm Knee Scale (LKS), respectively. Results: At 3 and 6 weeks post-TKA, LKS score was significantly higher in normal BMI group compared to overweight and obese. Lower BMI gained early improvement in functional outcome than higher BMI groups. However, patients showed considerable functional improvement at 6 months post-TKA, regardless of BMI category. Conclusion: Although BMI levels influence postoperative early functional improvement in TKA patients, the functional benefits after TKA at 6 months were similar regardless of BMI class.

The Use of Risk Scores in Patient Preoperative Optimization for Total Joint Arthroplasty: A Survey of Orthopaedic Nurse Navigators

Preoperative optimization of patients seeking total joint arthroplasty is becoming more common, and risk scores, which provide an estimate for the risk of complications following procedures, are often used to assist with the preoperative decision-making process. The aim of this study was to characterize the use of risk scores at institutions that utilize nurse navigators in the preoperative optimization process. The survey included 207 nurse navigators identified via the National Association of Orthopaedic Nurses to better understand the use of risk scores in preoperative optimization and the different factors that are included in these risk scores. The study found that 48% of responding nurse navigators utilized risk scores in the preoperative optimization process. These risk scores often included patient comorbidities such as diabetes (85%) and body mass index (87%). Risk scores are commonly used by nurse navigators in preoperative optimization and involve a variety of comorbidities and patient-specific factors.

Institutional Adherence to the American Association of Hip and Knee Surgeons Body Mass Index Guidelines Lowers Perioperative Emergency Department Visits in Primary Total Knee Arthroplasty

BACKGROUND

In 2013, the American Association of Hip and Knee Surgeons tasked a workgroup to provide obesity-related recommendations in total joint arthroplasty and determined that patients who had body mass index (BMI) ≥ 40 seeking hip/knee arthroplasty were at increased perioperative risk and recommended preoperative weight reduction. Few studies have shown the actual results of instituting this; therefore, we reported the effect of instituting a BMI < 40 threshold in 2014 on our elective, primary total knee arthroplasties (TKAs).

METHODS

We queried an institutional database to select all TKAs conducted from January 2010 to May 2020. There were 2,514 TKA pre-2014 and 5,545 TKA post-2014 that were identified. The 90-day emergency department (ED) visits, readmissions, and returns-to-operating room (OR) outcomes were identified. Patients were propensity score weight-matched as per comorbidities, age, initial surgical consultation (consult) BMI, and sex. We conducted 3 outcome comparisons: (1) pre-2014 patients who had a consult and surgical BMI ≥ 40 against post-2014 patients who had a consult BMI ≥ 40 and surgical BMI < 40; (2) pre-2014 patients against post-2014 patients who had a consult and surgical BMI < 40; (3) post-2014 patients who had a consult BMI ≥ 40 and surgical BMI < 40 against post-2014 patients who had a consult BMI ≥ 40 and surgical BMI ≥ 40.

RESULTS

Pre-2014 patients who had a consult and surgical BMI ≥ 40 had more ED visits (12.5% versus 6%, P = .002) but similar readmissions and returns-to-OR than post-2014 patients who had a consult BMI ≥ 40 and surgical BMI < 40. Pre-2014 patients who had a consult and surgical BMI < 40 had more readmissions (8.8% versus 6%, P < .0001) but similar ED visits and returns-to-OR when compared to their post-2014 counterparts. Post-2014 patients who had a consult BMI ≥ 40 and surgical BMI < 40 had fewer ED visits (5.8% versus 10.6%) but similar readmissions and returns-to-OR than patients who had a consult BMI ≥ 40 and surgical BMI ≥ 40.

DISCUSSION

Patient optimization prior to total joint arthroplasty is essential. Enacting BMI reduction pathways prior to total knee arthroplasty seems to afford morbidly obese patients major risk mitigation. We must continue to ethically balance the pathology, expected improvement after surgery, and the overall risks of complications for each patient.

LEVEL OF EVIDENCE

III.

Trajectories of Pain and Function Outcomes up to 5 to 8 Years Following Total Knee Arthroplasty

BACKGROUND

There appears to be substantial variability in outcomes > 2 years following total knee arthroplasty (TKA) that is masked by whole group analyses. The goal of the study was to identify trajectories of pain and function outcomes up to 5 to 8 years post-TKA and to identify baseline factors that are associated with different trajectories of recovery.

METHODS

Baseline, 6-month, and 12-month pain and function data were collected in a previous study investigating predictors of outcome following primary TKA (n = 286), along with a variety of baseline predictor variables. The present study obtained pain and function data at 5 to 8 years following TKA in the same cohort (n = 201). Latent class linear mixed models were used to identify different classes of pain and functional trajectories over time. The extent to which differences across latent classes were explained by baseline predictor variables was determined.

RESULTS

Three classes of pain and two classes of function trajectory were identified. While most patients (84% to 93%) followed a trajectory that showed an initial rapid gain following surgery that was sustained through 5 to 8 years, both pain and function included at least one trajectory class that showed a meaningful change after 12 months. No predictor variables were significantly associated with either the pain or function classes.

CONCLUSIONS

Most patients follow a traditional trajectory of recovery in knee pain and function over 5 to 8 years. However, alternative trajectories are observed in an important minority of patients such that knee pain and function at 12 months after surgery does not always reflect outcomes at 5 to 8 years.

Underweight Patients are at Increased Risk for Complications following Total Hip Arthroplasty

BACKGROUND

Given the prevalence of obesity in the United States, much of the adult reconstruction literature focuses on the effects of obesity and morbid obesity. However, there is little published data on the effect of being underweight on postoperative outcomes. This study aimed to examine the risk of low body mass index (BMI) on complications after total hip arthroplasty (THA).

METHODS

A large national database was queried between 2010 and 2020 to identify patients who had THAs. Using International Classification of Disease codes, patients were grouped into the following BMI categories: morbid obesity (BMI>40), obesity (BMI 30 to 40), normal BMI (BMI 20 to 30), and underweight (BMI<20). There were 58,151 patients identified, including 2,484 (4.27%) underweight patients, 34,710 (59.69%) obese patients, and 20,957 (36.04%) morbidly obese patients. Control groups were created for each study group, matching for age, sex, and a comorbidity index. Complications that occurred within 1 year postoperatively were isolated. Subanalyses were performed to compare complications between underweight and obese patients. Statistical analyses were performed using Pearson Chi-squares.

RESULTS

Compared to their matched control group, underweight patients showed increased odds of THA revision (Odds Ratio (OR) = 1.32, P = .04), sepsis (OR = 1.51, P = .01), and periprosthetic fractures (OR = 1.63, P = .01). When directly comparing underweight and obese patients (BMI 30 and above), underweight patients had higher odds of aseptic loosening (OR = 1.62, P = .03), sepsis (OR = 1.34, P = .03), dislocation (OR = 1.84, P < .001), and periprosthetic fracture (OR = 1.46, P = .01).

CONCLUSION

Morbidly obese patients experience the highest odds of complications, although underweight patients also had elevated odds for several complications. Underweight patients are an under-recognized and understudied high risk arthroplasty cohort and further research is needed.

Temporal trends in the rate of complications and prolonged length of stay relative to body mass index in patients undergoing total knee arthroplasty from 2012 to 2020

BACKGROUND

Elevated body mass index (BMI) is a risk factor for complications following total knee arthroplasty (TKA). Thus, we believe it is important to constantly re-evaluate the relationship between BMI and complication risk following TKA.

METHOD

Patients undergoing primary TKA were identified in a national database from 2012-2020. Rates of major complications, minor complications, and length of stay (LOS) greater than 2 days were calculated. The prevalence of postoperative outcomes were calculated per unit of BMI and then multiplied by a factor of 10^{^2} or 10^{^3} in order to create adjusted-BMI (aBMI). To isolate the effect of aBMI on postoperative outcomes, changes over time were analyzed using linear regression analysis controlling for age, sex, American Society of Anesthesiology (ASA) classification and smoking status.

RESULTS

365,333 patients were included. Mean BMI 33 ± 6.8. 10,616 (2.9%) of patients had a major postoperative complication, 9,345 (2.6%) minor complications, 3,277 (0.9%) had a deep or superficial surgical site infection (SSI). 133,563 (37%) of patients had LOS > 2 days. From 2012-2020, the ratio of major complications to aBMI decreased significantly by an average of -2.7% per year. The ratio of patients with LOS > 2 days to aBMI decreased significantly by -27% per year. The ratio of SSI to aBMI increased significantly by 10.8% per year.

CONCLUSIONS

From 2012 to 2020, the ratio of major complications and extended LOS following TKA as a function of BMI has decreased significantly, while the ratio of SSI as a function of BMI has doubled.

Risk of complications with prolonged operative time in morbidly obese patients undergoing elective total knee arthroplasty

BACKGROUND

Patients with a high body-mass index (BMI) are at increased risk for significant complications after total knee arthroplasty (TKA). We explored whether operative time is a modifiable risk factor for infectious and thromboembolic complications.

METHODS

A retrospective observational cohort study of the ACS-NSQIP registry, including all patients who underwent primary TKA (2015-2018), and were morbidly obese (BMI 40 kg/m² or greater) was performed. We created four categories of operative time in minutes: less than 60, 60-90, 91-120, and greater than 120. The association of prolonged operative time with superficial/deep surgical site infection (SSI), DVT and PE within 30 days postoperatively was evaluated using multivariate logistic regression.

RESULTS

34,190 patients were included (median age 63 [IQR 57-68], mean BMI of 44.6 kg/m² [SD 4.4]). The majority of patients had an operative time between 60-90 mins (n = 13,640, 39.9%) or 91-120 mins (n = 9908, 29.0%). There was no significant association between longer operative time and superficial/deep/organ-space SSI or PE. DVT risk was significantly increased. Patients with time exceeding 120 mins had nearly 2.5 greater odds of DVT compared to less than 60 minutes (OR 2.47, 95% CI: 1.39-4.39, P = 0.002). Odds of DVT were 1.73 times greater in those with time of 91-120 mins (OR 1.73, 95%CI: 0.98-3.05, P = 0.06).

CONCLUSION

Early infection and thromboembolic complications with prolonged operative time in morbidly obese patients remain low. We did not identify a significant association with increased operative time and superficial/deep SSI, or PE. There was a significantly increased risk for deep vein thrombosis with prolonged operative time.

Does Metabolic Syndrome Impact the Risk of Reoperation, Revision, or Complication After Primary Total Knee Arthroplasty?

BACKGROUND

Metabolic syndrome (MetS) is an increasingly frequent condition characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study evaluated implant survivorship, complications, and clinical outcomes of primary TKAs performed in patients who have MetS.

METHODS

Utilizing our institutional total joint registry, 2,063 primary TKAs were performed in patients with a diagnosis of MetS according to the World Health Organization criteria. MetS patients were matched 1:1 based on age, sex, and surgical year to those who did not have the condition. The World Health Organization's body mass index (BMI) classification was utilized to evaluate the effect of obesity within MetS patients. Kaplan-Meier methods were utilized to determine implant survivorship. Clinical outcomes were assessed with Knee Society scores. The mean follow-up was 5 years.

RESULTS

MetS and non-MetS patients did not have significant differences in 5-year implant survivorship free from any reoperation (P = .7), any revision (P = .2), and reoperation for periprosthetic joint infection (PJI; P = .2). When stratifying, patients with MetS and BMI >40 had significantly decreased 5-year survivorship free from any revision (95 versus 98%, respectively; hazard ratio = 2.1, P = .005) and reoperation for PJI (97 versus 99%, respectively; hazard ratio = 2.2, P = .02). Both MetS and non-MetS groups experienced significant improvements in Knee Society Scores (77 versus 78, respectively; P < .001) that were not significantly different (P = .3).

CONCLUSION

MetS did not significantly increase the risk of any reoperation after TKA; however, MetS patients with BMI >40 had a two-fold risk of any revision and reoperation for PJI. These results suggest that obesity is an important condition within MetS criteria and remains an independent risk factor.

LEVEL OF EVIDENCE

Level 3, Case-control study.

Tobacco Use Is Associated with More Severe Adverse Outcomes Than Morbid Obesity after Aseptic Revision TKA

The association of morbid obesity with increased revision total knee arthroplasty (rTKA) complications is potentially confounded by concurrent risk factors. This study was performed to evaluate whether morbid obesity was more strongly associated with adverse aseptic rTKA outcomes than diabetes or tobacco use history-when present as a solitary major risk factor. Demographic characteristics, surgical indications, and adverse outcomes (reoperation, revision, infection, and amputation) were compared between 270 index aseptic rTKA performed for patients with morbid obesity (n = 73), diabetes (n = 72), or tobacco use (n = 125) and 239 "healthy" controls without these risk factors at a mean 75.7 (range: 24-111) months. There was no difference in 2-year reoperation rate (17.8 vs. 17.6%, p = 1.0) or component revision rate (8.2 vs. 8.4%) between morbidly obese and healthy patients. However, higher reoperation rates were noted in patients with diabetes (p = 0.02) and tobacco use history (p < 0.01), including higher infection (p < 0.05) and above knee amputation (p < 0.01) rates in patients with tobacco use history. Multivariate analysis retained an independent association between smoking history and amputation risk (odds ratio: 7.4, 95% confidence interval: 1.7-55.2, p < 0.01). Morbid obesity was not associated with an increased risk of reoperation or component revision compared with healthy patients undergoing aseptic revision. Tobacco use was associated with increased reoperation and above knee amputation. Additional study will be beneficial to determine whether risk reduction efforts are effective in mitigating postoperative complication risks.

Pre- and Post-Operative Rehabilitation Interventions in Patients at Risk of Poor Outcomes Following Knee or Hip Arthroplasty: Protocol for Two Systematic Reviews

Objective

Total knee (TKA) and hip arthroplasty (THA) are successful procedures in treating end-stage osteoarthritis when nonoperative treatments fail. However, a growing body of literature has been reporting suboptimal outcomes following TKA and THA. While pre- and post-operative rehabilitation is imperative to recovery, little is known about their effectiveness for patients at risk of poor outcomes. In the 2 systematic reviews with identical methodology, we aim to evaluate the effectiveness of (a) pre-operative and (b) post-operative rehabilitation interventions for patients at risk of poor outcomes following TKA and THA.

Methods

The 2 systematic reviews will follow the principles and recommendations outlined in the Cochrane Handbook. Only randomized controlled trials (RCTs) and pilot RCTs will be searched in 6 databases: CINAHL, MEDLINE, Embase, Web of Science, Pedro, and OTseeker. Eligible studies including patients at risk of poor outcomes and evaluating rehabilitation interventions following and preceding arthroplasty will be considered for inclusion. Primary outcomes will include performance-based tests and functional patient-reported outcome measures, and secondary outcomes will include health-related quality of life and pain. The quality of eligible RCTs will be evaluated using the Cochrane's risk of bias tool, and the strength of evidence will be assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

Discussion

These reviews will synthesize the evidence regarding the effectiveness of pre-and post-operative rehabilitation interventions for patients at risk of poor outcomes, which in turn may inform practitioners and patients in planning and implementing the most optimal rehabilitation programs to achieve the best outcomes after arthroplasty.

Systematic Review Registration

PROSPERO CRD42022355574.

Can Technology Assistance be Cost Effective in TKA? A Simulation-Based Analysis of a Risk-prioritized, Practice-specific Framework

BACKGROUND

Robotic, navigated, and patient-specific instrumentation (PSI) TKA procedures have been introduced to improve component placement precision and improve implant survivorship and other clinical outcomes. However, the best available evidence has shown that these technologies are ineffective in reducing revision rates in the general TKA patient population. Nonetheless, it seems plausible that these technologies could be an effective and cost-effective means of reducing revision risk in clinical populations that are at an elevated risk of revision because of patient-specific demographics (such as older age at index surgery, elevated BMI, and being a man). Since clinical trials on this topic would need to be very large, a simulation approach could provide insight on which clinical populations would be the most promising for analysis.

QUESTIONS/PURPOSES

We conducted a simulation-based analysis and asked: (1) Given key demographic parameters characterizing a patient population, together with estimates of the precision achievable with selected forms of technology assistance in TKA, can we estimate the expected distributions of anticipated reductions in lifetime revision risk for that population and the associated improvements in quality-adjusted life years (QALYs) that would be expected to result? (2) Are there realistic practice characteristics (such as combinations of local patient demographics and capital and per-procedure costs) for which applying a per-patient risk-prioritized policy for using technology-assisted TKA could be considered cost-effective based on projected cost savings from reductions in revision rates?

METHODS

We designed simulations of hypothetical practice-specific clinical scenarios, each characterized by patient volume, patient demographics, and technology-assisted surgical technique, using demographic information drawn from other studies to characterize two contrasting simulated clinical scenarios in which the distributions of factors describing patients undergoing TKA place one population at a comparatively elevated risk of revision (elevated-risk population) and the second at a comparatively reduced risk of revision (lower-risk population). We used results from previous systematic reviews and meta-analyses to estimate the implant precision in coronal plane alignment for patient-specific instrumentation, navigated, and robotic technology. We generated simulated TKA patient populations based on risk estimates from large clinical studies, structured reviews, and meta-analyses and calculated the patient-specific reduction in the revision risk and the change in QALYs attributable to the technology-assisted intervention in each of the two simulated clinical scenarios. We also incorporated a sensitivity analysis, incorporating variations in the effect size of deviations from overall coronal alignment on revision risk and difference in health state utilities acquired through a structured review process. We then simulated the outcomes of 25,000 operations per patient using the precisions associated with the conventional TKA technique, the three technology-assisted techniques, and a hypothetical technology-assisted intervention that could consistently deliver perfectly neutral overall coronal alignment, which is unachievable in practice. A risk-prioritized treatment policy was emulated by ordering the simulated patients from the highest to lowest predicted increase in QALYs, such that simulated patients who would see the greatest increase in the QALYs (and therefore the greatest reduction in lifetime revision risk) were the patients to receive technology-assisted TKA intervention in a practice. We used cost estimates acquired through a structured review process and calculated the net added costs of each of the three technology-assisted techniques as a function of the percent utilization (proportion of patients treated with technology assistance in a practice), factoring in fixed costs, per-procedure variable costs, and savings occurring from the prevention of future revision surgery. Finally, we calculated the incremental cost-effectiveness ratio (ICER) and marginal cost-effectiveness ratio (MCER) for each technology-assisted technique for the two clinical scenarios. We then used a Monte Carlo approach to simulate variations in key patient risk, health state, and economic factors as well as to obtain a distribution of estimates for cost-effectiveness. We considered an intervention to be cost effective if either the ICER or MCER values were below USD/QALY 63,000.

RESULTS

For the lower-risk population, the median reduction in the revision risk was 0.9% (0.4% to 2.2%, extrema from the sensitivity analysis) and 1.8% (0.9% to 4.4%) for PSI and robotic TKA, respectively, and 1.9% (1.0% to 4.6%) for ideal TKA. In contrast, the median reduction in the revision risk in the elevated-risk clinical scenario was 2.0% (1.2% to 3.4%) and 4.6% (2.7% to 8.5%) for PSI and robotic TKA and 5.1% (3.0% to 9.4%) for ideal TKA. Estimated differences in the cumulative gain in QALYs attributable to technology-assisted TKA ranged from 0.6 (0.2 to 1.8) to 4.0 (1.8 to 10.0) QALYs per 100 patients, depending on the intervention type and clinical scenario. For PSI, we found treating 15% of patients in the lower-risk population and 77% in the elevated-risk population could meet the threshold for being considered cost effective. For navigated TKA systems offering high alignment precision, we found the intervention could meet this threshold for practice sizes of at least 300 patients per year and a percent utilization of 27% in the lower-risk population. In the elevated-risk population, cost-effectiveness could be achieved in practice volumes as small as 100 patients per year with a percent utilization of at least 6%, and cost savings could be achieved with a percent utilization of at least 45%. We found that robotic TKA could only meet the threshold for being considered cost-effectiveness in the lower-risk population if yearly patient volumes exceeded 600 and for a limited range of percent utilization (27% to 32%). However, in the elevated-risk patient population, robotic TKA with high alignment precision could potentially be cost effective for practice sizes as small as 100 patients per year and a percent utilization of at least 20% if a risk-prioritized treatment protocol were used.

CONCLUSION

Based on these simulations, a selective-use policy for technology-assisted TKA that prioritizes using technology assistance for those patients at a higher risk of revision based on patient-specific factors could potentially meet the cost-effectiveness threshold in selected circumstances (for example, primarily in elevated-risk populations and larger practice sizes). Whether it does meet that threshold would depend significantly on the surgical precision that can be achieved in practice for a given proposed technology as well as on the true local costs of using the proposed technology. We further recommend that any future randomized trials seeking to demonstrate possible effects of technology assistance on revision risk focus on clinical populations that are at higher risk of revision (such as, patient populations that are relatively younger, have higher BMIs, and higher proportions of men).

CLINICAL RELEVANCE

This study suggests that technology assistance is only likely to prove cost effective in selected circumstances rather than in all clinical populations and practice settings. In general, we project that surgical navigation is most likely to prove cost effective in the widest range of circumstances, that PSI may be cost effective or cost neutral in a moderate range of circumstances, and that robotic surgery is only likely to be cost effective in moderately large practices containing patients who are on average at an intrinsically elevated risk of revision.

Preoperative Risk Management Programs at the Top 50 Orthopaedic Institutions Frequently Enforce Strict Cutoffs for BMI and Hemoglobin A1c Which May Limit Access to Total Joint Arthroplasty and Provide Limited Resources for Smoking Cessation and Dental Care

BACKGROUND

Performing elective orthopaedic surgery on patients with high BMI, poorly controlled hyperglycemia, and who use tobacco can lead to serious complications. Some surgeons use cutoffs for BMI, hemoglobin A1c, and cigarette smoking to limit surgery to patients with lower risk profiles rather than engaging in shared decision-making with patients about those factors. Other studies have suggested this practice may discriminate against people of lower income levels and women. However, the extent to which this practice approach is used by orthopaedic surgeons at leading hospitals is unknown.

QUESTIONS/PURPOSES

(1) How often are preoperative cutoffs for hemoglobin A1c and BMI used at the top US orthopaedic institutions? (2) What services are available at the top orthopaedic institutions for weight loss, smoking cessation, and dental care? (3) What proportion of hospital-provided weight loss clinics, smoking cessation programs, and dental care clinics accept Medicaid insurance?

METHODS

To investigate preoperative cutoffs for hemoglobin A1c and BMI and patient access to nonorthopaedic specialists at the top orthopaedic hospitals in the United States, we collected data on the top 50 orthopaedic hospitals in the United States as ranked by the 2020 US News and World Report 's "Best Hospitals for Orthopedics" list. We used a surgeon-targeted email survey to ascertain information regarding the use of preoperative cutoffs for hemoglobin A1c and BMI and availability and insurance acceptance policies of weight loss and dental clinics. Surgeons were informed that the survey was designed to assess how their institution manages preoperative risk management. The survey was sent to one practicing arthroplasty surgeon, the chair of the arthroplasty service, or department chair, whenever possible, at the top 50 orthopaedic institutions. Reminder emails were sent periodically to encourage participation from nonresponding institutions. We received survey responses from 70% (35 of 50) of hospitals regarding the use of preoperative hemoglobin A1c and BMI cutoffs. There was no difference in the response rate based on hospital ranking or hospital region. Fewer responses were received regarding the availability and Medicaid acceptance of weight loss and dental clinics. We used a "secret shopper" methodology (defined as when a researcher calls a facility pretending to be a patient seeking care) to gather information from hospitals directly. The use of deception in this study was approved by our institution's institutional review board. We called the main telephone line at each institution and spoke with the telephone operator at each hospital asking standardized questions regarding the availability of medical or surgical weight loss clinics, smoking cessation programs, and dental clinics. When possible, researchers were referred directly to the relevant departments and asked phone receptionists if the clinic accepted Medicaid. We were able to contact every hospital using the main telephone number. Our first research question was answered using solely the surgeon survey responses. Our second and third research questions were addressed using a combination of the responses to the surgeon surveys and specific hospital telephone calls.

RESULTS

Preoperative hemoglobin A1c cutoffs were used at 77% (27 of 35) of responding institutions and preoperative BMI cutoffs were used at 54% (19 of 35) of responding institutions. In the secret shopper portion of our study, we found that almost all the institutions (98% [49 of 50]) had a medical weight loss clinic, surgical weight loss clinic, or combined program. Regarding smoking cessation, 52% (26 of 50) referred patients to a specific department in their institution and 18% (9 of 50) referred to a state-run smoking cessation hotline. Thirty percent (15 of 50) did not offer any internal resource or external referral for smoking cessation. Regarding dental care, 48% (24 of 50) of institutions had a dental clinic that performed presurgical check-ups and 46% (23 of 50) did not offer any internal resource or external referral for dental care. In the secret shopper portion of our study, for institutions that had internal resources, we found that 86% (42 of 49) of weight loss clinics, 88% (23 of 26) of smoking cessation programs, and 58% (14 of 24) of dental clinics accepted Medicaid insurance.

CONCLUSION

Proceeding with TJA may not be the best option for all patients; however, surgeons and patients should come to this consensus together after a thoughtful discussion of the risks and benefits for that particular patient. Future research should focus on how shared decision-making may influence patient satisfaction and a patient's ability to meet preoperative goals related to weight loss, glycemic control, smoking cessation, and dental care. Decision analyses or time trade-off analyses could be implemented in these studies to assess patients' tolerance for risk.

CLINICAL RELEVANCE

Orthopaedic surgeons should engage in shared decision-making with patients to develop realistic goals for weight loss, glycemic control, smoking cessation, and dental care that consider patient access to these services as well as the difficulties patients experience in losing weight, controlling blood glucose, and stopping smoking.

The Association of Metabolic Syndrome on Complications and Implant Survivorship in Primary Total Knee Arthroplasty in Morbidly Obese Patients

BACKGROUND

Metabolic syndrome (MetS) includes interrelated conditions such as insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study sought to determine the association of MetS in morbidly obese patients (body mass index >40) on complications and clinical outcomes after primary total knee arthroplasty (TKA).

METHODS

A retrospective review was performed to include all morbidly obese patients who underwent primary elective TKA for osteoarthritis at a single academic institution. Patients who did and did not have MetS were propensity-matched 1:1 based on baseline characteristics. A total of 391 patients who did and 935 who did not have MetS were included having a mean body mass index of 44.2 (range, 40.0 to 68.9).

RESULTS

The MetS patients had longer lengths of stay (LOS) (3.5 ± 2.4 versus 3.0 ± 1.5 days, P = .001) and were more likely to be discharged to skilled nursing facilities (23.8 versus 15.3%, P = .007). At 90 days postoperatively, major (P = .756) and minor (P = .652) complication rates and readmissions (P = .359) were similar. Revision rates as well as improvements in KOOS-JR, and VR-12 mental and physical component scores from preoperative to 1 year (P = .856, P = .524, and P = .727, respectively) postoperatively did not significantly differ between groups. MetS and non-MetS patients had similar 5-year freedom from all-cause revision (90.2 versus 94.2%, P = .791).

CONCLUSION

Morbidly obese patients who have MetS had longer LOS and higher discharges to skilled nursing facilities. The 90-day complications, readmissions, revision rates, and patient-reported outcomes were similar, suggesting that resource allocation should be focused on perioperative protocols that can help optimize LOS and discharge dispositions in morbidly obese MetS patients undergoing TKA.

LEVEL OF EVIDENCE

III.

Information and BMI limits for patients with obesity eligible for knee arthroplasty: the Swedish surgeons' perspective from a nationwide cross-sectional study

BACKGROUND

In the past decades, the incidence of obesity has increased worldwide. This disease is often accompanied with several comorbidities and therefore, surgeons and anesthesiologists should be prepared to provide optimal management for these patients. The aim of this descriptive cross-sectional study was to map the criteria and routines that are used by Swedish knee arthroplasty surgeons today when considering patients with obesity for knee arthroplasty.

METHODS

A survey including 21 items was created and sent to all the Swedish centers performing knee arthroplasty. The survey included questions about the surgeons' experience, hospital routines of preoperative information given and the surgeons' individual assessment of patients with obesity that candidates for knee arthroplasty. Descriptive statistics were used to present the data.

RESULTS

A total of 203 (64%) knee surgeons responded to the questionnaire. Almost 90% of the surgeons claimed to inform their patients with obesity that obesity has been associated with an increased risk of complications after knee arthroplasty. Seventy-nine percent reported that they had an upper BMI limit to perform knee arthroplasty, a larger proportion of the private centers had a BMI limit compared to public centers. The majority of the centers had an upper BMI limit of 35.

CONCLUSION

The majority of the knee arthroplasty surgeons in Sweden inform their patients with obesity regarding risks associated with knee arthroplasty. Most centers that perform knee arthroplasties in Sweden have an upper BMI limit.

Decrease in acute periprosthetic joint infections incidence with vancomycin-loaded calcium sulfate beads in patients with non-modifiable risk factors. A randomized clinical trial

OBJECTIVES

The influence of local antibiotic therapy in orthopedic surgery remains unclear. In this trial, we evaluated the incidence of periprosthetic joint infections (PJI), after local or intravenous (IV) antibiotic prophylaxis. The aim of this intervention was to compare the PJI incidence in a population with non-modifiable risk factors after local prophylaxis with vancomycin-loaded calcium sulfate beads versus a control group.

METHODS

A total of 83 subjects were evaluated, inclusion criteria included participants over 60 years of age, with at least one main risk factor for PJI who underwent total hip or knee joint replacement between June 2019 and May 2020. Cases were randomized, and the intervention group received local prophylactic antibiotic therapy with calcium sulfate beads impregnated with vancomycin; conventional IV prophylactic antibiotic therapy was administered for the control group. C-reactive protein (CRP) and erythrocyte sedimentation rate (ERS) serum biomarkers were analyzed on the day 5 and weeks 4, 8, and 12. When needed, the synovial fluid sample was obtained and cultured for the early acute PJI diagnosis.

RESULTS

Acute PJI was found in 27 patients (67.5%) in the control group and 4 (9.3%) in the intervention group. The variable analysis identified that local prophylaxis with calcium sulfate beads reduces the incidence of acute knee or hip PJI in patients with non-modifiable risk factors compared to conventional prophylaxis (p < 0.0001) with a relative risk of 0.13 (CI:0.05-0.35). Length of hospital stay was also shorter in the intervention group at 4.6 days, compared to 15.25 days in the control group; p < 0.001.

CONCLUSIONS

Local antibiotic prophylaxis in patients with non-modifiable risk factors undergoing hip or knee replacement reduces the incidence of acute PJI compared to IV antibiotics.

CLINICAL TRIALS

NCT03976466 (clnicaltrials.gov) LEVEL OF EVIDENCE: II.

The Evolution, Current Indications and Outcomes of Cementless Total Knee Arthroplasty

Total knee arthroplasty (TKA) has been performed by orthopedic surgeons for decades, but the cementless TKA has only recently gained much interest in the world of arthroplasty. Initially, early designs had multiple complications, particularly with aseptic loosening due to osteolysis and micromotion. However, modifications have shown good outcomes and excellent survivorship. Over the last several decades, changes in implant designs as well as implant materials/coatings have helped with bone in growth and stability. Furthermore, surgeons have been performing TKA in younger and more obese patients as these populations have been increasing. Good results from the cementless TKA compared to cemented TKA may be a better option in these more challenging populations, as several studies have shown greater survivorship in patients that are younger and have a greater BMI. Additionally, a cementless TKA may be more cost effective, which remains a concern in today's healthcare environment. Overall, cemented and cementless TKA have great results in modern times and there is still a debate as to which implant is superior.

Do obese patients benefit from a kinematic, appropriately designed total knee prosthesis?

Introduction

Modern total knee arthroplasty (TKA) using the Journey 2 implant utilizes a bicruciate stabilized (BCS) technique. However, whether bicruciate stabilized TKA is equally effective across weight classes is unknown.

Methods

We identified patients who underwent primary bicruciate stabilized TKA during 2016 and 2017, at a single institution. All included patients had, at minimum, 2-year follow-up. Patients were categorized into body-mass index (BMI) groups as follows: underweight, normal, or overweight (<30 kg/m2), obese (≥30 to <35 kg/m2), and severely obese (≥35 kg/m2). Patient reported outcome measures (PROMs) were measured at baseline. Both KSS and KOOS JR, along with the Visual Analogue Scale (VAS), were also recorded at follow-up. Pre-operative, post-operative, and pre-to post-operative changes in PROMs were analyzed using analysis of variance (ANOVA) and linear regression.

Results

The 292 patients had a mean age of 64.8 years and mean BMI of 32.3 kg/m2. There were 116 (39.7%) patients in the underweight, normal, or overweight group, 88 (30.1%) in the obese category, and 88 (30.1%) in the severely obese group. There were no differences between PROMs at baseline or at follow-up (p > 0.10 for all comparisons). There were also no differences in the improvement from pre-to post-operative KSS (p = 0.21) and KOOS JR (p = 0.62).

Conclusions

Bicruciate stabilized TKA has similar effects on PROMs across BMI groups. These results suggest that bicruciate stabilized TKA is a viable treatment option both for low-weight and high-weight patients.

Impact of being underweight on peri-operative and post-operative outcomes of total knee or hip arthroplasty: A meta-analysis

BACKGROUND

Many systematic reviews have focused on assessing the effect of body mass index (BMI) on the outcomes and complications associated with total hip arthroplasty (THA) and total knee arthroplasty (TKA), but primarily dealt with obesity compared to normal weight (NW). None of these reviews attempted to assess the effect of low BMI or underweight (UW) compared to NW in patients undergoing THA or TKA.

AIM

This review aims to compare specific operative outcomes such as operation duration, length of hospital stay, and post-operative complications including mortality, infections, deep vein thrombosis, etc. along with re-hospitalization and reoperation rates between UW and NW patients undergoing THA, TKA or both.

METHODS

An electronic search was performed in PubMed, Scopus, Excerpta Medica database (EMBASE), Web of Science (WoS), and Cochrane Central Register of Controlled Trials (CENTRAL) along with a manual search. The quality of the studies was assessed using the Newcastle-Ottawa scale for cohort studies. The data were subjected to both qualitative and quantitative analysis.

RESULTS

Thirteen retrospective and five prospective cohort studies were included. The quality of included studies was assessed to be good to fair. The length of hospital stay after TKA or THA was found to be significantly higher for UW patients when compared to NW patients, with a mean difference: 0.39 95%CI: [0.06, 0.72], P = 0.02 (in days). Studies presenting both THA and TKA together as total joint arthroplasty showed an increased incidence of mortality in patients treated with THA or TKA alone, Odds ratio: 4.18 95%CI: [2.88, 6.07]. A higher incidence of post-operative complications was also observed in UW patients undergoing THA.

CONCLUSION

UW patients undergoing THA or TKA had a higher incidence of post-operative complications and were associated with a higher readmission rate. Moreover, UW patients were associated with an increased incidence of mortality in the studies that reported THA and TKA together.

Optimización preoperatoria del paciente antes de una artroplastia de cadera o rodilla: parte 1

Las artroplastias de cadera y rodilla son estrategias que han demostrado ser efectivas en el tratamiento de la patología degenerativa articular. El reemplazo articular mejora la calidad de vida de la mayoría de los pacientes cuando el tratamiento conservador falla. Sin embargo, estas son cirugías mayores que conllevan un riesgo significativo de complicaciones, incluyendo la necesidad de una revisión. El propósito de este artículo es analizar los factores de riesgo modificables del paciente antes de la cirugía, a finde disminuir el riesgo de complicaciones posoperatorias. Estudios recientes han descripto ciertos factores de riesgo modificables, inherentes al paciente y que incrementan la posibilidad de complicaciones posoperatorias luego de un reemplazo articular de cadera o rodilla. Estos incluyen obesidad, malnutrición, tabaquismo, diabetes, anemia, deficiencia de vitamina D, consumo de opioides, artropatías inflamatorias, insuficiencia renal crónica y colonización por estafilococco meticilino-resistente. Si conseguimos optimizar estas condiciones durante el preoperatorio, reduciremos el riesgo de complicaciones posoperatorias.

Operative Techniques to Reduce Hip and Knee Arthroplasty Complications in Morbidly Obese Patients

Obesity, defined as a body mass index (BMI) >30, is associated with an increased likelihood of osteoarthritis and need for total joint arthroplasty (TJA). Unfortunately, the morbidly obese population has a higher risk of postoperative complications. For some surgeons, patient selection criteria for TJA includes BMI<40. The associated risks are recognized by The American Association of Hip And Knee Surgeons, and many surgeons follow these guidelines. Importantly, as obese patients have been demonstrated to have equal or greater gains in functional outcomes and quality of life metrics, it is important for obese patients to have access to TJA. Through a comprehensive literature review and structured interviews with leading surgeons in the field, we provide guidance for orthopedic surgeons treating patients with BMI>40 to minimize risks, including tailored preoperative, intraoperative, and postoperative considerations.